1. FIELD OF THE INVENTION
The present invention relates to the construction for an assembly for mounting a solenoid valve which is used for controlling operations of a speed change control valve or for other purposes in a vehicle transmission or other devices.
2. DESCRIPTION OF PRIOR ART
In the prior art, a solenoid valve is used for a speed change control valve in a vehicle transmission, and this type of solenoid valve is usually mounted on a housing of the transmission or on a housing of the speed change control valve (which are called "base member" hereinafter). In this case, the solenoid valve comprises a valve section which works as a hydraulic valve for switching oil paths and a solenoid section which generates a force to move a spool of this hydraulic valve, and various devices and propositions have been made for their configurations and constructions to mount them on a housing.
For instance, a construction wherein an oil path and a valve seat are mounted on a base board mounted on a base member and a valve body, a solenoid, and a magnetic tube are mounted on the base board is disclosed in Japanese Patent Publication No. 38468/1991.
Also, a construction wherein an undercover is mounted via a separator plate on a valve body (base member) and an oil path for a solenoid valve is formed on this under cover with a solenoid valve provided facing this oil path is disclosed in Japanese Patent Laid Open Publication No. 278068/1990.
In the conventional constructions for mounting a solenoid valve as described above, an oil path for a solenoid valve is generally winding and complicated, so it is difficult to form an oil path with a large cross-sectional area and resistance in the oil path is apt to become larger, which is a problem to be solved.
Also, in a case where a plurality of solenoid valves are to be provided, wiring is required for each solenoid, so the wiring is apt to become complicated, which will in turn result in a complicated wiring harness. It should be noted that a construction wherein a circuit board is provided on a member for mounting a solenoid valve to simplify the wiring is proposed in Japanese Patent Laid Open Publication No. 87491/1989. In this case, however, a separate circuit board is required, which results in an increase of parts as well as increase of its cost.
In addition, in the prior art, it is required to directly mount the solenoid valve on the base member, so that operating sounds and vibrations generated by the solenoid valve are directly delivered to the base member, which often generates noises.